Rex Stout and his seventy some Nero Wolfe novels are generally regarded as amongst the greatest mystery novels ever written. They read as fresh today as when the series started in 1934, and they can pretty much be read in any order. The plot of AND BE A VILLAIN centers around a cyanide poisoning that had happened during a live radio talkshow broadcast, a few days before the novel opens. The victim was a race track bookie. Also present at the crime scene was a mathematician, to provide expert commentary on probability, and some respectability for the show to even dare have a bookie on air. (But to the reader, the mathematician is mostly to provide comic relief.) When Nero Wolfe interviews the mathematician, the latter launches into an uninterruptible spiel about how he always wanted to apply probability theory to detective work, and talks math for a bit, going so far as to write out the "second approximation to the normal distribution", which Archie Goodwin, the novel's narrator, reproduces. Apparently Archie doesn't know what a square root symbol is, since what should be a sqrt(2.pi.D) comes out as V.2.pi.D. (It appears Stout did his homework, so either his printer got it wrong, or Stout engaged in an inside joke for mathematicians only.)